Rolling mill for metal rods



May 14, 1968 K. J. NEU MANN ROLLING MILL FOR METAL RODS Filed May 10, 1965 o w w o n O O o o mq .K o b h o o O O O c mi N O O O O Wk 3 D o O United States Patent O 3,382,697 ROLLING MILL FQR METAL RODS Karl Josef Nenmann, St. Ingbert, Saar, Germany, assignor to Verwaltungsgesellschaft Moeller um] Neumann Offene Handelsgesellschaft, St. Ingbert, Saar, Germany Filed May 10, 1965, Ser. No. 454,424 Claims priority, application Germany, May 11, 1964,

7 Claims. (Cl. 72-226) ABSTRACT OF THE DISCLOSURE This invention comprises a rolling mill for metal rods and the like having two rolling lines arranged in substantially parallel relationship. Each of the rolling lines include a breakdown group of rolling stands, a finishing group of rolling stands, and a plurality of intermediate horizontal rolling stands between the breakdown and finishing groups for successive treatment of heated rods continuously and simultaneously fed to the breakdown groups. Single-core rolling of the rods is performed in the breakdown groups and in the finishing groups and twocore rolling of the rods is performed in the intermediate stands.

The invention relates to a rolling mill for producing metal rods, particularly rods of high-grade steel, in which two continuously operating preliminary or breakdown rolling groups are provided which are fed either by two furnaces or by one common furnace having two discharge openings. Behind the breakdown rolling groups several intermediate rolling groups are disposed which are followed by single core finishing groups on each of two rolling lines one of which may be selectively connected to the rolling lines of each of the two breakdown groups.

A known rolling mill of this type has two breakdown groups with a different number of stands in each. The breakdown group having the largest number of stands is used only for rolling material of small dimensions and the group with the smaller number of stands is used only for material of larger dimensions. The purpose of this double arrangement of breakdown groups is to avoid the difficulties encountered in changing a single continuous breakdown group to a different program.

The invention employs a double breakdown group for a very different purpose connected with the problem of increasing the production with a two core or two lane rolling system, to obtain a high production with the lowest possible number of stands, which is actually the basic purpose of double core rolling. In the case of the mentioned rolling mill having two unequal breakdown groups, the rolling operation is carried out in two cores only in one breakdown group and subsequently in a single core rolling operation in the finishing groups. In that case as in similar cases only the production based on the supply from one furnace may be obtained. The invention is directed to a rolling process for the production of material of the same dimensions but providing a switching or moving around of rolling stands between the rolling lines in order to obtain a maximum production.

The invention provides a rolling process and apparatus in which at least one of the breakdown groups has horizontal and vertical stands and the intermediate stands arranged between the breakdown groups and the finishing groups of one line are designed for two-core rolling fr m the one-core operating breakdown groups.

It will thus be understood that according to the present invention single core rolling is carried out in two parallel breakdown groups, two core rolling is carried out in an intermediate group and again single core rolling in the fin- 3,332,697 Patented May 14, 1968 ishing group. Of course, the larger dimension may be rolled straight through in single core operation on both lines of the breakdown groups. Due to the fact that at least one of the breakdown groups has a horizontal-vertical arrangement of the stands, which means single-core operation, it is not necessary to carry out any turning. Compared to breakdown groups including only horizontal stands it is possible to operate, due to the elimination of the need for turning with greater entrance sections in the breakdown groups which provides a higher production. Because the intermediate stands are designed for two core rolling this output increase is obtained, aside from an additional breakdown group and an oven, without a larger number of stands.

The breakdown group or groups in a horizontal-vertical arrangement have the further advantage that the stands may be placed closer together than if turning is necessary. Besides the space saving the temperature drop of the rolled material is also smaller, which is already considerable, because the rolling speed in the breakdown groups is so small that a cooling with water is necessary. Furthermore the advantage is obtained that in the two furnaces two different qualities of base material may be employed, as indicated previously.

The novel features and advantages of the invention will become apparent from the following description taken in connection with the attached drawing which illustrates an example of a steel rolling mill according to the invention comprising successive rolling groups in four different rolling programs. In the drawing:

FIGURE 1 shows the arrangement for rolling the smallest dimensions, and

FIGURES 2, 3 and 4 show arrangements for rolling larger dimensions of rolling stock.

On the two rolling lines 1 and 2 two breakdown rolling groups 3 and 4 are arranged in a horizontal-vertical arrangement of the stands which are fed by two furnaces or by a common furnace with two discharge openings. It is obvious that different qualities of steel can only be rolled if two furnaces are provided.

On rolling line 2 for the small dimensions intermediate groups 5, 6 and 7 are provided which are designed for two core rolling. The preliminary profiles from the breakdown group 3 are conducted to the first intermediate group 5 over a deviation 8. Behind the last intermediate group 7 two finishing groups 9 and 10 are provided in which the rolling operation is completed in two cores.

In the arrangement of FIGURE 1 the smallest dimension is rolled completely in two cores including the last intermediate group 7 after which one core passes over the deviation 11 into the finishing group 9 and the other core continues straight into the finishing group 10. It will be understood that in rolling the smallest dimension where the greatest number of passes is required all the stands except the preliminary and finishing stands are employed for the stand saving two core rolling operation. The single core finishing operation is particularly suited for the purpose of imparting tolerance life to the rolled stock, the single core breakdown rolling without turning to increase the entrance sections for the breakdown groups and thus produces a production increase.

The invention employs moveable intermediate stands in order to limit the total number of stands. The intermediate stands comprise according to the invention the groups 5, 6 and 7 which are arranged at such intervals that behind each intermediate group a change-over to single core finishing rolling may be carried out. In this manner it is possible to interrupt the two core intermediate rolling behind each intermediate group in order to move from the succeeding intermediate group the necessary number of stands to the other rolling line 1 so that this line contains more stands while the other one is reduced by the 1 2 same number. It is appropriate to make half the stands of the intermediate groups 6 and 7 moveable and, depending on the dimensions to be rolled, one can place on both rolling lines l and 2 an equal number of stands behind the particular intermediate group which still operates on a two core arrangement.

If for example according to FIGURE 1 for mm. round material 18 passes are necessary, one moves according to FIGURE 2 the two last stands of the intermediate group '7 to the rolling line 1 and builds in a deviation track 12. There are available thus for each core 16 passes in order to roll for example 12 mm. round material.

For mm. round material for example, there are moved according to FIGURE 3 additionally the two last stancs of the intermediate group 6 and one obtains 14 passes for each core. The single core rolling operation begins for this most difficult dimension, which is still intermediately rolled in a two core arrangement, after the intermediate group 5 for which a deviation track 13 must be erected.

In the example shown the first intermediate grou 5 has only two non-moveable stands. Therefore one obtains according to FIGURE 4 an uneven number of stands on the two rolling lines 1 and 2 when the two last stands of intermediate groups 6 and 7 are moved to the rolling line 1.

In this arrangement, thus without the deviations 8, 12 and 13, the rolling operation is single core straight through from the breakdown groups 3 and 4 so that on rolling line 1 twelve passes are made for mm. round material and on line 2 fourteen passes for 18 mm. round material.

Larger dimensions can be rolled in each arrangement when individual stands are provided with blind or idle passes or when the rolls are moved apart.

It is also possible to roll different dimensions simultaneously on both rolling lines in that for example in the arrangement according to FIGURES 1 or 2 the rolling operations is carried out from each breakdown group single core straight through.

The rolling mill according to the invention may also be designed as a double rolling mill with two independently driven rolling lines 1 and 2 containing a relatively small number of stands in which all the intermediate stands may be moved to one line and the preliminary rolled pieces coming from the separate breakdown groups .3 and 4 being rolled two core.

For reasons of cost or because a high production is not yet required the rolling mill may be constructed in two building steps so that first only one breakdown group is provided which has only horizontal stands and in Which two core rolling is carried out. Such a rolling mill lies within the scope of the invention it there is left sufficient room for a second rolling group and an additional furnace or if a furnace with two discharge openings is provided.

The production increase which is obtained by the second breakdown group in an H-V-arrangement of the stands due to the higher entrance sections and the higher capabilities of the rolling mill amounts to about 50% of a rolling mill having only one two core breakdown group.

It is also possible to make provisions in the first building step for having subsequently both break-down groups in an H-V-arrangement. In that case the breakdown group to be built first is partly provided with so-called combination stands in which the rolling stands may be operated in horizontal as well as vertical rolling positions.

What is claimed is:

1. A rolling mill for metal rods or the like comprising, in combination, two rolling lines arranged in substantially parallel relationship, each of said rolling lines including a breakdown group of rolling stands and a finishing group of rollin stands arranged for single-core rolling, at least one of said breakdown groups being provided with horizontal and vertical rolling stands for simultaneous operation or said breakdown group for single-core rolling of said rods, means for continuously supplying heated rod to both of said breakdown groups simultaneously, a plurality of intermediate horizontal rolling stands arranged in association with both or" said rolling lines between said breakdown groups and said finishing groups for two-core rolling of said rods, and means for guidably conveying said rods from said breakdown groups to said intermediate rolling stands and from said intermediate rolling stands to said finishing groups.

2. A rolling mill in accordance with claim 1 wherein said breakdown group in each of said rolling lines is provided with horizontal and vertical rolling stands.

3. A rolling mill in accordance with claim 1 wherein all of said intermediate rolling stands are positioned in one of said rolling lines.

4. A rolling mill in accordance with claim 3 wherein at least one intermediate rolling stand is arranged for movement between said rolling lines for selective Singlecore rolling of said rods on corresponding portions of both of said roll lines.

5. A rolling mill in accordance with claim 1 wherein said plurality of intermediate rolling stands are arranged into intermediate groups for successive rolling of said rods, at least one intermediate group adjacent said finishing groups having rolling stands arranged for movement between said roll lines to permit single-core rolling of said rods on corresponding portions of both of said roll lines.

6. A rolling mill in accordance with claim 5 wherein at least two successive intermediate groups adjacent said finishing groups are provided with said movable rolling stands.

7. A rolling mill in accordance with claim 6 wherein each of said two successive intermediate groups is provided with an even number of rolling stands and wherein one half of the rolling stands in said two successive intermediate groups are arranged for movement between said roll lines.

References Cited UNITED STATES PATENTS 3,129,617 4/1964 Schulte 72-227 1,932,750 10/1933 Rendleman 72-228 3,197,993 8/ 1965 Hein et al 72230 FOREIGN PATENTS 1,057,048 5/1959 Germany.

1,071,025 5/1958 Germany.

CHARLES W. LANHAM, Primary Examiner.

H. D. HOINKES, Assistant Examiner. 

